/*
 *   Copyright (c) 2006,2007 Daniel Mack, Tim Ruetz
 *
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation; either version 2 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program; if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
*/

#include <linux/init.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/input.h>
#include <linux/usb.h>
#include <linux/spinlock.h>
#include <sound/driver.h>
#include <sound/core.h>
#include <sound/rawmidi.h>
#include <sound/pcm.h>
#include "caiaq-device.h"
#include "caiaq-input.h"

#ifdef CONFIG_SND_USB_CAIAQ_INPUT

static unsigned char keycode_ak1[] =  { KEY_C, KEY_B, KEY_A };
static unsigned char keycode_rk2[] =  { KEY_1, KEY_2, KEY_3, KEY_4, 
					KEY_5, KEY_6, KEY_7 };

#define DEG90  (range/2)
#define DEG180 (range)
#define DEG270 (DEG90 + DEG180)
#define DEG360 (DEG180 * 2)
#define HIGH_PEAK (268)
#define LOW_PEAK (-7)

/* some of these devices have endless rotation potentiometers
 * built in which use two tapers, 90 degrees phase shifted.
 * this algorithm decodes them to one single value, ranging
 * from 0 to 999 */
static unsigned int decode_erp(unsigned char a, unsigned char b)
{
	int weight_a, weight_b;
	int pos_a, pos_b;
	int ret;
	int range = HIGH_PEAK - LOW_PEAK;
	int mid_value = (HIGH_PEAK + LOW_PEAK) / 2;

	weight_b = abs(mid_value-a) - (range/2 - 100)/2;
	
	if (weight_b < 0)
		weight_b = 0;

	if (weight_b > 100)
		weight_b = 100;

	weight_a = 100 - weight_b;

	if (a < mid_value) {
		/* 0..90 and 270..360 degrees */
		pos_b = b - LOW_PEAK + DEG270;
		if (pos_b >= DEG360)
			pos_b -= DEG360;
	} else
		/* 90..270 degrees */
		pos_b = HIGH_PEAK - b + DEG90;


	if (b > mid_value)
		/* 0..180 degrees */
		pos_a = a - LOW_PEAK;
	else
		/* 180..360 degrees */
		pos_a = HIGH_PEAK - a + DEG180;

	/* interpolate both slider values, depending on weight factors */
	/* 0..99 x DEG360 */
	ret = pos_a * weight_a + pos_b * weight_b;

	/* normalize to 0..999 */
	ret *= 10;
	ret /= DEG360;

	if (ret < 0)
		ret += 1000;
	
	if (ret >= 1000)
		ret -= 1000;

	return ret;
}

#undef DEG90
#undef DEG180
#undef DEG270
#undef DEG360
#undef HIGH_PEAK
#undef LOW_PEAK


static void snd_caiaq_input_read_analog(struct snd_usb_caiaqdev *dev, 
					const char *buf, unsigned int len)
{
	switch(dev->input_dev->id.product) {
	case USB_PID_RIGKONTROL2:
		input_report_abs(dev->input_dev, ABS_X, (buf[4] << 8) |buf[5]);
		input_report_abs(dev->input_dev, ABS_Y, (buf[0] << 8) |buf[1]);
		input_report_abs(dev->input_dev, ABS_Z, (buf[2] << 8) |buf[3]);
		input_sync(dev->input_dev);
		break;
	}
}

static void snd_caiaq_input_read_erp(struct snd_usb_caiaqdev *dev, 
				     const char *buf, unsigned int len)
{
	int i;

	switch(dev->input_dev->id.product) {
	case USB_PID_AK1:
		i = decode_erp(buf[0], buf[1]);
		input_report_abs(dev->input_dev, ABS_X, i);
		input_sync(dev->input_dev);	
		break;
	}
}

static void snd_caiaq_input_read_io(struct snd_usb_caiaqdev *dev, 
				    char *buf, unsigned int len)
{
	int i;
	unsigned char *keycode = dev->input_dev->keycode;

	if (!keycode)
		return;

	if (dev->input_dev->id.product == USB_PID_RIGKONTROL2)
		for (i=0; i<len; i++)
			buf[i] = ~buf[i];

	for (i=0; (i<dev->input_dev->keycodemax) && (i < len); i++)
		input_report_key(dev->input_dev, keycode[i], 
					buf[i/8] & (1 << (i%8)));

	input_sync(dev->input_dev);
}

void snd_usb_caiaq_input_dispatch(struct snd_usb_caiaqdev *dev, 
				  char *buf, 
				  unsigned int len)
{
	if (!dev->input_dev || (len < 1))
		return;

	switch (buf[0]) {
	case EP1_CMD_READ_ANALOG:
		snd_caiaq_input_read_analog(dev, buf+1, len-1);
		break;
	case EP1_CMD_READ_ERP:
		snd_caiaq_input_read_erp(dev, buf+1, len-1);
		break;
	case EP1_CMD_READ_IO:
		snd_caiaq_input_read_io(dev, buf+1, len-1);
		break;
	}
}

int snd_usb_caiaq_input_init(struct snd_usb_caiaqdev *dev)
{
	struct usb_device *usb_dev = dev->chip.dev;
	struct input_dev *input;
	int i, ret;

	input = input_allocate_device();
	if (!input)
		return -ENOMEM;

	input->name = dev->product_name;
	input->id.bustype = BUS_USB;
	input->id.vendor  = usb_dev->descriptor.idVendor;
	input->id.product = usb_dev->descriptor.idProduct;
	input->id.version = usb_dev->descriptor.bcdDevice;

        switch (dev->chip.usb_id) {
	case USB_ID(USB_VID_NATIVEINSTRUMENTS, USB_PID_RIGKONTROL2):
		input->evbit[0] = BIT(EV_KEY) | BIT(EV_ABS);
		input->absbit[0] = BIT(ABS_X) | BIT(ABS_Y) | BIT(ABS_Z);
		input->keycode = keycode_rk2;
		input->keycodesize = sizeof(char);
		input->keycodemax = ARRAY_SIZE(keycode_rk2);
		for (i=0; i<ARRAY_SIZE(keycode_rk2); i++)
			set_bit(keycode_rk2[i], input->keybit);

		input_set_abs_params(input, ABS_X, 0, 4096, 0, 10);
		input_set_abs_params(input, ABS_Y, 0, 4096, 0, 10);
		input_set_abs_params(input, ABS_Z, 0, 4096, 0, 10);
		snd_usb_caiaq_set_auto_msg(dev, 1, 10, 0);
		break;
	case USB_ID(USB_VID_NATIVEINSTRUMENTS, USB_PID_AK1):
		input->evbit[0] = BIT(EV_KEY) | BIT(EV_ABS);
		input->absbit[0] = BIT(ABS_X);
		input->keycode = keycode_ak1;
		input->keycodesize = sizeof(char);
		input->keycodemax = ARRAY_SIZE(keycode_ak1);
		for (i=0; i<ARRAY_SIZE(keycode_ak1); i++)
			set_bit(keycode_ak1[i], input->keybit);

		input_set_abs_params(input, ABS_X, 0, 999, 0, 10);
		snd_usb_caiaq_set_auto_msg(dev, 1, 0, 5);
		break;
	default:
		/* no input methods supported on this device */
		input_free_device(input);
		return 0;
	}

	ret = input_register_device(input);
	if (ret < 0) {
		input_free_device(input);
		return ret;
	}

	dev->input_dev = input;
	return 0;
}

void snd_usb_caiaq_input_free(struct snd_usb_caiaqdev *dev)
{
	if (!dev || !dev->input_dev)
		return;

	input_unregister_device(dev->input_dev);
	input_free_device(dev->input_dev);
	dev->input_dev = NULL;
}

#endif /* CONFIG_SND_USB_CAIAQ_INPUT */